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Erectile dysfunction (ED) can be defined as a consistent or recurrent inability to achieve and/or maintain a penile erection sufficient for sexual activity. It is a common sexual problem that GPs will be familiar with seeing in men of all ages, and which increases with age.1 Men with ED may find that it causes a significant impact on their quality of life, as well as that of their partner’s. Erectile dysfunction may be thought of as a symptom rather than a specific disease, and is associated with many comorbidities.

Prevalence

Reported figures for prevalence of ED vary considerably. This is likely due to several factors, including different patient populations, methodologies, and definitions for ED. That said, there is a clear association between ED and increasing age. A high-quality review of epidemiological ED literature in 2013 confirmed this, and provided some useful figures for prevalence across studies (see Table 1).1

Table 1: Prevalence of ED in different age groups1

Age (years)

Prevalence (%)

Median

Range

40–49

6

1–29

50–59

12

3–50

60–69

32

7–74

70–79

44

26–76

Comorbidities with erectile dysfunction

Attaining an erection involves a complex interplay between psychological, hormonal, neurological, vascular, and tissue components. Conditions that affect any of these can therefore be associated with ED. Table 2 outlines some important pathophysiological factors.2

It should be noted that ED may be the first presentation of some medical conditions, including diabetes, hypertension, and cardiovascular disease (CVD). Indeed, it is now well established that ED represents a crucial marker for the onset of CVD, potentially presenting a valuable window of opportunity to focus on primary prevention.3

It is now increasingly recognised that male lower urinary tract symptoms (LUTS) are closely linked to ED—probably sharing some of the same pathophysiology. It seems that most men seeking treatment for either LUTS or ED will in fact have both conditions.4

Role of primary care

The invaluable role of the primary care team starts by creating an environment in which a man feels comfortable discussing his symptoms. Confidence in asking men about sexual matters gets easier with practice. Some healthcare professionals benefit from various courses that are available in taking a sexual history, such as those offered by the STI Foundation.

It is unwise to make assumptions about sex life in older people. A large global study found that approximately one-half of men in their 70s had been sexually active in the last year.5

There are certainly some men for whom targeted questions about possible ED may be considered, such as those with diabetes, CVD, LUTS, or depression. For example, while no longer part of the quality and outcomes framework, a recommendation to offer men the opportunity to discuss ED as part of their annual review is included in the latest NICE guideline on type 2 diabetes in adults.6

Simple questions practitioners can ask may go along the lines of: ‘It is well known that men with “X” are more likely to have problems with their erections: is that something you have noticed to be an issue?’ Giving permission for men to discuss their ED symptoms is often hugely appreciated, and a dedicated appointment can then be arranged to explore any issues further.

Initial assessment and diagnosis

Primary care is well placed to arrange the initial assessment of ED.7 Duration, severity, and any precipitants of symptoms should be explored. Some clinicians and patients will prefer to complete a questionnaire to ‘score’ ED symptoms, which allows a considered assessment of different components. In the author’s experience, the most commonly used scale is the abbreviated version of the International Index of Erectile Function, the IIEF-5.8

In addition to establishing the severity of symptoms, it is important to understand the degree of bother that the ED is causing a man and/or his partner, as this will vary considerably between people. A relationship history is important, and a past medical history may be relevant, focusing on related comorbidities (see Table 2). Practitioners should also ask about:

smoking

alcohol

any other substance misuse.

Assessing and subsequently addressing mental health issues can be crucial. The aetiology of ED is sometimes divided into psychogenic and organic, and while practitioners may find more of the former in younger men and more of the latter in older men, the picture is often mixed. Nocturnal erections are more commonly maintained in psychogenic cases, but by no means always.

Examination of the genitalia will occasionally reveal abnormalities, such as plaques in Peyronie’s disease, or phimosis; these will often require referral to specialist care, depending on the severity and degree of bother. Blood tests are recommended and should include lipids, glucose/‌HbA1c, and morning (before 11 am) testosterone levels.7 Clinical suspicion may prompt a full blood count or thyroid function tests.

The 2015 NICE Guideline 12 on Suspected cancer9 recommends that practitioners consider a digital rectal examination (DRE) and prostate specific antigen (PSA) test in men with ED; however, in the author’s opinion, this has caused controversy in urological circles, as it is rare for ED and prostate cancer to be causally linked. Practitioners should assess DRE and PSA if testosterone replacement therapy is considered.7

Management

Among the causes of ED, any that are reversible should, of course, be addressed where possible (e.g. sedentary lifestyle, medications, smoking, adverse lipid profile, poor diabetic control, and hypogonadism). This can range from a simple medication review to a specialist assessment for diagnosed hypogonadism (e.g. a total serum testosterone consistently <12 nmol/l, on a minimum of two morning samples.7,10)

Lifestyle factors

Addressing lifestyle factors has been shown to improve erectile function; these factors include:11

smoking

alcohol consumption

obesity

physical activity.

This will also help treat associated morbidities, such as CVD risk and hypogonadism.11 There may also be a role for regular pelvic floor exercises.12

Psychosexual counselling

While access to psychosexual counselling is not always straightforward, it should certainly be considered for cases where a strong psychogenic component of the ED is suspected. For example, younger men with relatively sudden onset of ED that then proves to be longstanding are especially likely to benefit.

First-line therapy

For most men with ongoing confirmed ED, first-line treatment will be a phosphodiesterase-5 inhibitor (PDE5I). In the UK, for understandable cost issues, the current favoured initial choice is sildenafil, which at the time of writing (June 2017) is the only PDE5I available for ED to all men on an NHS prescription;13 however, this may change as soon as patents expire for other treatments. NHS prescriptions for other PDE5Is (see Table 3) are limited to those men meeting the Schedule 2 (Selected List Scheme) criteria.

Table 3: Important differences between phosphodiesterase-5 inhibitors

PDE5I

Maximum concentration (hrs)14

Approximate half-life (hrs)14

Effect of food on absorption of drug15

NHS prescriptions for all13

Sildenafil 100 mg

1

3

Reduced absorption

Yes

Tadalafil 20 mg

2

17.5

None

No

Vardenafil 20 mg

1

4

Reduced absorption

No

Avanafil 200 mg

0.5–0.75

6

Reduced absorption

No

Phosphodiesterase-5 inhibitors are, on the whole, very safe medications. There is no evidence that currently licensed ED treatments add to CVD risk in patients with or without previously-diagnosed CVD.7 In terms of any CVD risk, encouraging sexual activity with ED medications is generally considered safe for men who can comfortably walk 1 mile on flat terrain in 20 minutes, or briskly climb two flights of stairs in 10 seconds.16

Co-administration of PDE5Is with nitrates should be avoided due to risk of hypotension. If a patient is taking nitrate containing-medications, there may be an opportunity to switch these to alternative medications. Alpha-blockers should be co-prescribed with caution.15

Common side-effects of PDE5Is include:15

headache

flushing

nasal congestion

dyspepsia

back pain

myalgia.

Reported rates of these vary with different PDE5Is, so switching to another PDE5I may be helpful if side-effects occur and are problematic to the individual.2

It is essential to emphasise to men that they should not just expect an erection to spontaneously arrive after taking a PDE5I. Inform patients that they need to wait approximately 1 hour, and then will still require adequate sexual stimulation to achieve an erection. Increased physical stimulation becomes more important with age.

Men should be encouraged to try at least eight doses of the maximally tolerated dose of a PDE5I before being classed as ‘non-responders’.7 Identifying men who do not respond to PDE5I therapy is made much easier by arranging a follow-up appointment, for example, 2 months after the start of treatment. At the follow up, confirm with the patient that the medication is being used correctly, and if so, try switching the dosage from ‘as-needed’ to ‘daily use’—this will resolve the situation for a good proportion of people who have not previously responded to treatment. Local referral pathways are likely to exist to help guide when to refer on. As an illustration, the BNF states: ‘Patients who fail to respond to the maximum dose of at least two different phosphodiesterase type-5 inhibitors should be referred to a specialist.’

Tadalafil 2.5–5 mg is a licensed once-daily option (the 5 mg dose is also licensed for benign prostatic hyperplasia).17 Sildenafil has a shorter half-life compared with tadalafil; however, its licence states one dose in 24 hours (with a maximum single dose of 100 mg),18 so (similarly to tadalafil) it can be taken daily rather than as required. It has been noted that taking sildenafil every night can increase nocturnal erections and successful sexual activity, with the current advantage of being much cheaper compared with tadalafil.19

It is of interest that the use of daily sildenafil is recommended as an early option in published UK recommendations for treatment of ED that is either post-surgical20 or resulting from radical radiotherapy and androgen deprivation therapy for prostate cancer.21

Second-line therapy

There are several other options that can be prescribed for ED; however, confidence in prescribing these therapies in primary care may vary, and help from community or secondary-care clinics may be sought.

Vacuum erection devices can be very effective, but counselling in proper use is important. These devices are listed as a first-line treatment in the British Society for Sexual Medicine erectile dysfunction guideline; however, in real-life practice, accessing counselling on appropriate use is much more difficult than prescribing PDE5Is in primary care. Long-term use varies, but there is good uptake in men who find these devices helpful.7

Alprostadil can be introduced into the penis in various ways: via intracavernosal injection, intra-urethral pellets, or topically to the urethral meatus, in the form of a cream. Another type of licensed intracavernosal injection uses an aviptadil/phentolamine mix.7

It can sometimes be helpful to try various combinations of PDE5Is with these second-line medications.

Third-line therapy

There is increasing interest in the use of low-intensity extracorporeal shockwave therapy to treat ED,22 but evidence is inconsistent, and it is not widely available in the UK.

When all other therapies have failed, it is important that primary care clinicians are aware of the option of penile implants, which may be funded on the NHS for some patients (often men who have experienced ED after surgery, radiotherapy, or trauma).

When to refer

While most men with ED can be managed in primary care, some will need referring for further investigation (see Box 1).7

Box 1: Indications for specialist investigations7

The following are indications for specialist referral:

young men who have always had difficulty in obtaining and/or sustaining an erection

men with a history of trauma

where an abnormality of the testes or penis is found on examination

men who are unresponsive to medical therapies and may desire surgical treatment.

Useful resources

For clinicians:

British Society for Sexual Medicine: Guidelines on the management of erectile dysfunction7

Erectile dysfunction is a condition that presents very commonly in primary care, particularly in older men with certain co-morbidities. There are many possible co-morbidities associated with ED, and ED in itself may represent a risk factor for developing established cardiovascular disease.

Previous advice on restricting prescribing PDE5Is has perhaps created an impression that effective treatment options are limited; however, these restrictions have now been lifted for generic sildenafil, with other PDE5Is likely to follow soon. Beyond these medications, practitioners and patients alike should be assured that many other effective management strategies exist, and can usually be accessed by specialist referral when appropriate.

Key points

The prevalence of ED rises steeply with age

Numerous comorbidities should be considered in patients with ED, especially diabetes, CVD, and depression

GP commissioning take home messages for England

Erectile dysfunction is a common disorder and GPs should be aware that it can be a possible symptom of other important pathologies, and not just a problem in its own right

NHS commissioners should liaise with public health commissioners to ensure that ED services are jointly commissioned and available through sexual health clinics

Commissioners could (with support from specialist sexual health providers) construct a care pathway for the management of ED, this should include all the necessary tests and examinations that primary care should consider

the pathway should clearly identify referral criteria to specialist care and commissioners should ensure that these specialist care services are available locally

Local formularies should identify the licensed indications and doses of available ED medications, and identify what medications are available on the NHS and for which indication.

Topics

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This CPD activity consists of 5 multiple-choice questions (MCQs) designed to test your knowledge on assessing and managing erectile dysfunction (ED) in primary care—you will then be prompted to reflect on your learning.